Siemens SINAMICS S120 - Servo Solenoid Valve; Valve Amplifier; Shutoff Valve

System overview
2.1 Structure of a hydraulic drive
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
27
2.1.3
Servo solenoid valve
Task
The servo solenoid valve is the final controlling element in the control loop and forms the
electro-hydraulic converter.
Function
The valve continuously converts electrical signals into hydraulic flow.
Its quality is defined by static and dynamic parameters, such as:
● Zero overlap
● Hysteresis
● Frequency limit
2.1.4
Valve amplifier
The valve amplifier contains the power electronics for the solenoids in the servo solenoid
valve, which the valve spool moves.
The position controller in the valve amplifier (onboard electronics – OBE) controls the
position of the valve spool proportionally to the manipulated variable (U = -10 ... +10 V).
2.1.5
Shutoff valve
Shutoff valves are used to add safety functions to a valve control with servo solenoid valve.
Shutoff valves can prevent uncontrolled motion of the cylinder.
Special designs include a sensor for the mechanical position of the valve spool (monitoring
for increased safety).